Mixing apparatus



March 31. 1925.

s. S.'GET T|NGS ET AL MIXING APPARATUS Y-FM' Filed Sept. 2'7, 1924 Patented Mar. 31, 1925.

UNITED STATES P 1531,38? ATENT OFFFCE.

SYDNEY SAIiTER GETTINGS AND W'ALTER LIGHT BOIDMAN, O'F DORKING, ENGLAND,

ASSIGNORS TO JAMES MITCHELL THOMAS JOHNSTON,:OF-LONDON, ENGLAND.

MIXING APPARATUS.

Application filed September 27, 1924. Serial No. 740,257.

To all whom it may concern:

Be it known that we, SYDNEY SALTER Gn'r- TINGS, a subject of the King of England, and WVAL rER LIGHT BODMAN, a subject of the King of England, both residing at Dorking, Surrey, England, have invented certain new and useful Improvements in Mixing Apparatus, of which the following is a specification.

This invention relates to mixing apparatus and more particularly to means for mixing molten bitumen with sand and other materials for the preparation of road-surfacing agglomerates.

It is known that the use of bitumen in this connection requires a higher temperature than suffices in the case of gas tar for example, as employed in making tar macadam and that it is not practicable to heat the mixer by means of steam in order to main tain the bitumen in condition for eflicient mixing with sand or fine stone. 7

The most favourable temperature for the molten bitumen is between 340'and 360 F, with an aggregate at a temperature of 270 to 300 F., giving an effective temperature for the mixture of about 2&0 F., after allowing for losses by radiation and conduction. Since the normal temperature of stcan'i at lOOllOS. per square inch (gauge pressure) is only 337 F., the required heating of the bitumen cannot be obtained unless very high pressure steam is employed. In the case offlue gases however the temperature may be from 450 to 800 'F., which provides an ample margin for the requisite heating. 7

According to the present invention, therefore, the mixing apparatus is'constructed so as to be heated by flue gases derived for, example from the furnace of a melting tank or steam boiler, these flue gases being led to a. heating chamber beneath the base of the mixer and upwards through a hollow centre piece which forms the baseot' the chimney. This centre piece is preferably constructed as a rotary driver for scrapers operating continually upon the bottom of the pan to prevent deposits thereon, an equalizing beam mounted in the centre piece supporting two diametrically opposite knives or scrapers. A transverse bridge connecting the bearers upon which the p n is carried provides a support for therotary centre piece and its driving gear, while leaving space for the admission ofsandor stone to the mixing 7 pan. 1

The pan is preferably suspended from its bearers by means of screw jacks, allowing it to be lowered away from the rotary centre piece and scrapers when desired.

The invention is hereatterdescribed with reference to the accompanying drawings, in which Figure 1 is an elevation, partlyin section, of the preferred form of construction.

Figure 2 is a plan of the same.

- Figure 3 is a part sectional elevation of the apparatus, viewed at right angles to .Figure 1.

Figure-4 is a sectional elevation of the lower end of the chimneyf V The improved apparatus comprises a suitable framing such as'channel-steel joists. or bearers 1 arranged to-' support steel construction; the pan is fitted with a renewable cast iron base.3 having an inclination from the centre outwards and downwards. of approximately 15,this base being lodged at sufficient distance from the 1 a stationary mixing chamber or pan2 preferably of sheet chamber for cleaning. The centre of the inclined base opens-out into a hollow boss 3 of diameter equal to that of the flue, the gases passing upward through this boss into a revolving uptake or centre piece 5 leading to the main chimney.

The centre p ece 5. is supported by a transverse bridge 6 and rotated by means of bevel gearing 7 for example, from a shaft 8 driven through a load-limitingfriction clutchby a sprocket wheel connected to the motor, a diametrically disposedheavybeam or cross bar 9 is mounted inthe centre piece, and from the ends of this cross-beam the-re as pend a pair of knives or scrapers 10 revolving in contact with the base 3 of the mixing pan and shaped to conform thereto. The knife-carrying beam, 9 1s preferably mounted in the centre piece 5 by engagemove slightly in position to equalize its pressure on the knives or to permit the latter to ride over any obstructions. The knives may be secured by means of vertical angle irons 1O bolted or otherwise fastened at their upper ends to the fiat sides of the beam 9 and having the knives attached by screws to their lower ends; as'seen in Fig ure 2 the angle irons 10 are placed cornerwise upon the cross-beam so as to give the required angular setting to the blades. The centre piece also carries one or more knives 10 adapted to scrape the material from around the inner part or boss 3 of the panbottom, so that the several knives effect a complete scraping of the entire bottom surface of the pan.

The molten bitumen is delivered into the pan from the heating tank by means of a pipe 11 discharging into an open scoop 12 projecting from one side of the pan 2, and communicating with the interior of the latter at about the normal level of the contents, so as to reduce the internal splashing as far as possible.

Any suitable means may be provided for admitting the sand or other material to be mixed with the bitumen, this material enter-, ing the pan on either side of the bridge 6.

A discharge door 13 is-provided at one side of the pan,'being carried for example by a cross shaft 13 mounted on the bearers 1 which support the pan; any suitable locking device is employed for maintaining this door normally closed, and a spout 13 is fitted beneath the door for directing the mixed materials when discharged from the pan.

The flue gases are conducted through a suitable trunk or conduit 14 into the heating jacket or chamber 4: beneath the mixing pan, the admission being preferably tangential to give a swirling actlon; the gases pass upwards through the mouth or boss 3 of the conically domed base 3 into the interior of the revolving centre piece 5. The horizontalbridge 6, formed for example by a casting with a central aperture in line with the centre piece, and providing a bearing for the latter and its driving gear 7 carries by means of a flanged cap 6 which encloses the gearing 7, a stationary chimney 15 which is preferably fitted with a steam jet 16 for producing draught. This chimney may be constructed of sheet iron and fitted internally with a coned. liner 15 to form a trap for condensation from the steam jet, the water being led away through a drain pipe 15" to avoid any entrance of moisture into the mixing pan. An inspection door or slide 15 may be arranged on the wall of the chimney to allow removal of accumulated dust or cinders. r

The mixing pan 2 is suspended from the bearers 1 upon the machine frame by means of a pair of screw jacks 17 provided with gases to theheating chamber.

combination a mixing chamber, agitating means therein, a heating chamber beneath said mixing chamber, a partition between the two chambers having a central aperture and constituting the floor of the mixlng chamber, an uptake within the mixing chamber in communication with the said central aperture, and means for delivering heated 2. A mixing apparatus comprising in combination a mixing chamber, a heating chamber beneath said mixing chamber, a partition between the two chambers having a central aperture and constituting the floor of the mixing chamber, an uptake mounted to rotate'about its vertical axis and communicating with the said central aperture, mixing blades carried by said uptake, eans for rotating the uptake and means for delivering heated gases to the heating chamber.

3. A mixing. apparatus comprising in combination a drum having its axis vertical. a transverse partition therein sloping upwards from its margin towards its central portion and having said central portion formed as an upwardly projecting cylindrical body open at its upper end, agitating means within the drum above the partition. and means for delivering heated gases to the space withinthe drum below the partition.

1. A mixing apparatus comprising in combination a drum'having its axis vertical, a transverse partition therein formed with an upwardly projecting hollow central portion, an uptake rotatably mounted within the drum above/the partition and having its lower end surrounding the extremity of the said hollow central portion, mixing blades carried by said uptake, means for rotating the uptake,- nd means for delivering heated gases to the space beneath the partition.

5. A mixing apparatus comprising in combination a mixing chamber, a heating chamber beneath said mixing chamljier, a partition beneath-the two chambershaving a central aperture and constituting the Floor of the mixing chamber, an uptake within the mixing clian'iberin conniuinication with the said central aperture and mounted to rotate aboutits vertical axis, a beam carried by said uptake transversely thereof and free to rock in a vertical direction, mixing blades 12 1 6. A. mlxing apparatus lOnl l'lSlllg in (ill combination a mixing chamber, a heating chamber beneath said mixing chamber, a partition beneath the two chambers having a central aperture and constituting the floor of the mixing chamber, an uptake within the mixing chamber in communication with the said central aperture and mounted to rotate about its vertical axis, a beam carried by said uptake transversely thereof and free to rock in a vertical direction, mixing blades carried by said'beam on opposite sides of the uptake, further mixing blades carried directly by the uptake, means for rotating the uptake and means for delivering heated gases to the heating chamber.

7. A mixing apparatus comprising in combination a drum having its axis vertical, a transverse partition therein formed with an upwardly projecting hollow central portion, an uptake rotata-bly mounted within the drum above the partition and having its lower end surrounding the extremity of the said hollow central portion, mixing blades carried by said uptake, and in contact with the floor of the mixing chamber, means for rotating the uptake, and means for delivering heated gases to the space heneath the partition.

8. A mixing apparatus comprising in combination a mixing chamber, a heating chamber beneath said mixing chamber, a partition beneath the two chambers having a central aperture and constituting the floor of the mixing chamber, an uptake within the mixing chamber in communication with the said central aperture and mounted to rotate about its vertical axis, a beam carried by said uptake transversely thereof and free to rock in a vertical direction, mixing blades carried by said beam on opposite sides of the uptake audin contact with the floor of the mixing chamber, means for rotating the uptake whereby said blades scrape the said floor, and means for delivering heated gases to the heating chamber.

9. A. mixing apparatus comprising in combination a mixing chamber, a heating chamber beneath said mixing chamber, a partition beneath the two chambers having a central aperture and constituting the floor of the mixing chamber, an uptake within the mixing chamber in communication with the said central aperture and mounted to rotate about its vertical axis, a beam carried by said uptake transversely thereof and tree to rock in a. vertical direction, mixing blades carried by said beam on opposite sides of the uptake and in contact with the floor of the mixing chamber, further mixing blades carried directly by the uptake and in contact with the floor of the mixing chamber, means for rotating the uptake whereby said blades scrape the said floor, and means for delivering heated gases to the heating chamber.

it, and means for delivering heated gases to the space within the drum below the partition. v

11.. A mixing apparatus oomprislng. in

combination a mixing chamber, a heating chamber below the mixing chamber, said two chambers having a wall common to both of them, means for delivering heated gases to the heating chamber, a conduit for heated gases within the mixing chamber communicating with the heating chamber through said common wall, agitating means within the mixing chamber, a; supporting member surmounting the mixing chamber, and adjustable means for suspending the mixing chamber from said supporting member.

12. A mixing apparatus comprising in combination a mixing chamber, a heating chatmber below the mixing chamber, said two chambers having a wall common to both of them, means for delivering heated gases to the heating chamber, a conduit for heated gases within the mixing chamber communicating with the heating chamber through said common wall, agitating means within the mixing chamber, a supporting member surmounting the mixing chamber and adjustable screw-and-nut means for suspending the mixing chamber from said supporting member.

13. A mixing apparatus comprising in combination a mixing chamber, a heating chamber beneath the mixing chamber, agitating means within said mixing chamber,

means for delivering heated gases to the heating chamber, a chimney communicating with the heating chamber and extending through the mixing chamber, a draught-inducing steam jet within said chimney, a conical liner within said chimney, having its wide lower end secured to the chimney wall, and an outlet conduit for condensation water extending through the chimney wallv immediately above the junction of said liner therewith.

In testimony whereofv we l'iavo signed our names to this specification 1n the presence of two subscribing witnesses.

SYDNEY SALTER GETTINGS.

TALTER LIGHT BODM-AN. iVitnesses:

S. G. FILER,

D. MA N. 

